You should be aware that the PDF Lib documentation says that this method should return a textflow handle that can then be used on subsequent calls (i.e. to have an arbitrary number of boxes and have the text continue to spill over). It does not, at least not in my version of PHP (4.3.8). I had to dig around and find a message in the official message boards saying it does NOT work this way. The only way to do textflow is to use pdf_fit_textflow() and grab the locations of the target box each time.